Method for controlling a hydraulically-actuated fuel injection system

Claim 3

A method, as set forth in claim 1, including the steps of: sensing an actual actuating fluid pressure and producing an actual actuating fluid pressure signal (P f ) indicative of the magnitude of the sensed actuating fluid pressure; comparing the desired actuating fluid pressure signal (P d ) with the actual actuating fluid pressure signal (P f ) and producing an actuating fluid pressure error signal (P e ) in response to a difference between the compared actuating fluid pressure signals (P df ,P f ); and receiving the actuating fluid pressure error signal (P e ), determining the desired electrical current based on the actuating fluid pressure error signal (P e ), and producing the desired electrical current signal (I).

Claim 4

A method, as set forth in claim 2, wherein the desired fluid pressure is determined to cause the fuel injector (25) to produce a plurality of injections during compressive strokes at engine cranking speeds.

Claim 5

A method, as set forth in claim 3, including the steps of: receiving the temperature signal (T c ), and producing a maximum duration signal (m d ) whose magnitude oscillates between a duration range that is a function temperature, the maximum duration signal indicating the period over which fuel is to be injected; and receiving the maximum duration signal (m d ), and delivering an actual time duration signal (t d ) to the injector (25) to electronically control the injection period.